<template>
  <div id="app">
    <el-row :gutter='20'>
      <el-col :span='6'>
        <div class="bg-red"></div>
      </el-col>
      <el-col :span='6'>
        <div class="bg-yellow"></div>
      </el-col>
      <el-col :span='6'>
        <div class="bg-red"></div>
      </el-col>
      <el-col :span='6'>
        <div class="bg-yellow"></div>
      </el-col>
    </el-row>
  </div>
</template>
<style>
*{
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}
.box {
  width: 100vw;
  height: 100vh;
}
.bg-yellow {
   height: 100vh;
  width: 100%;

  background-color: yellow;
}
.bg-red {
  height: 20px;
  width: 100%;
  background-color: red;
}
</style>
